In recent years, an electric vehicle, a fuel cell vehicle, a hybrid electric vehicle and the like using electricity as a driving force instead of an internal combustion engine have drawn attention. In these vehicles, power is obtained by supplying electrical energy stored in batteries to motors via inverters and driving them. Since high-currents flow through these inverters, heat generated at electronic components called power semiconductors such as IGBTs (insulated-gate type bipolar transistors) constituting the inverters increases. Accordingly, a cooling device having a large cooling capacity for cooling the electronic components is required.
Patent Document 1 (Japanese Patent Application Publication No. 2008-221951) discloses a method in which an electronic component (an inverter 10) is fixed directly on a cooling device including a metal pipe, and a coolant is caused to flow in the metal pipe of the cooling device to cool the electronic component.